The invention relates generally to semiconductor and component packaging technology and in particular to a method and apparatus for providing line terminating networks for a semiconductor chip package.
In a typical printed wiring board configuration, a mounting socket is electrically connected, permanently, for example by wave soldering, to the printed wiring board, and a semiconductor package is inserted into the socket. Discrete components are connected between the printed wiring board socket connections and, for example, termination potentials required by the semiconductor chip for proper operation. As the number of terminals on the semiconductor chip package grows, the available space on the printed wiring board becomes increasingly crowded and, for example, it may occur that fewer semiconductor packages can be mounted on a board because of the number of discrete components required therefor.
One solution to this problem is to employ planar technologies to produce planar components within the printed wiring board itself, for example the many termination resistors required by the semiconductor package. This solution to the component crowding problem is expensive, however, because of the large number of initially rejected boards which have one or more bad parts embedded therein. As a result, the manufacturing process of employing planar technology in the printed wiring board requires several additional quality control and rework process steps to ensure that a large board, which may contain as many as, for example, five thousand planar termination resistors, is acceptable.
Furthermore, when dealing with high density ECL technology, the number of routing channels, normally two for other semiconductor technologies, increases to three, and further, ECL technology requires that the routing channel connection be made first to the terminal of the semiconductor socket and then to the terminating component. There results therefore a severe congestion in the printed wiring board.
Primary objects of the invention, therefore, are to alleviate the component crowding on a printed wiring board and to provide faster, more reliable circuitry, and to connect semiconductor packages to a printed wiring board in a manner which is less expensive than that previously known. Other objects of the invention are to increase the density of semiconductor functions on a printed wiring board, thereby increasing the compactness and speed of the circuitry.